Old dogs can teach humans new things about evolution. After
studying North American dog fossils from as far back as 40 million
years ago, Brown scientists have concluded that changes in climate can
directly impact predators as well as animals who feed only on plants.

Courtesy Mauricio Anton

“Although this seems logical,” says one of the study’s authors,
Christine Janis, a Brown professor of ecology and evolutionary biology,
“it hadn’t been demonstrated before.” The conclusion suggests another
evolutionary change that could be triggered by climate change.

Fossils show that 40 million years ago dogs, which are native to North
America, had adapted to their wooded habitat as small animals that
looked more like mongooses than today’s canines.

Beginning a few million years later, the North American climate cooled,
the Rocky Mountains expanded, and the continent’s interior became
drier. As forests slowly gave way to open grasslands, dogs responded by
evolving from ambushers to pursuit-pounce predators similar to modern
coyotes or foxes and ultimately wolves.

The lead author of the study, whose results were published in Nature
Communications, was Borja Figueirido, a former Brown Fulbright
postdoctoral researcher. He and Janis argue that today’s climate change
will likely further affect dogs’ evolution.

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